Hyaluronidase: An overview of its properties, applications, and side effects

Evolved enzymes in the metabolism of biological poly-acids: Applications in otolaryngological biocatalysis

This study explores evolved Hyaluronidase, Lipase, and Elastase's identification, characterization, and therapeutic potential to enhance tissue regeneration and drug delivery systems in otolaryngology. Hyaluronidase variant H5 exhibited a turnover number (k_cat) of 1500 min-1, a 200 % increase over wild-type (500 min-1), demonstrating superior hyaluronic acid degradation. Similarly, lipase variant L2 reached 1200 min-1 (400 min-1 wild-type), and elastase variant E3 showed a turnover of 2200 min-1 (1000 min-1 wild-type). Kinetic analyses revealed improved Km and Vmax values across variants, with Hyaluronidase Variant H5 achieving Km = 1.5 μM and Vmax = 3000 μM/min. Molecular Dynamics (MD) simulations indicated structural stability (average RMSD ~1.5 Å for H5) and strong hydrogen bonding (180 bonds), enhancing catalytic efficiency. In vitro assays demonstrated a 40 % enhancement in tissue regeneration and increased epithelial cell proliferation (100 % for Hyaluronidase Variant H5 vs. 60 % wild-type). In vivo studies in rabbits revealed a 30 % reduction in recovery time post-sinus surgery and a 50 % reduction in scar tissue formation. These findings underscore the potential of evolved enzymes in advancing drug delivery (DD) and tissue repair (TR), with implications for broader applications in wound healing and inflammatory diseases.

Considerations for Proper Use of Hyaluronidase in the Management of Hyaluronic Acid Fillers

Effective management of complications from hyaluronic acid (HA) fillers is crucial in aesthetic medicine. This article examined the role of hyaluronidase in addressing adverse effects associated with HA fillers, such as nodules, vascular occlusions, and excessive volume. It highlights the enzyme's ability to degrade HA, thereby resolving issues that may arise from filler treatments. The discussion includes practical aspects of using hyaluronidase, such as recommended dosing, injection techniques, and potential risks. The benefits of hyaluronidase, including its rapid action in dissolving problematic fillers and its role in improving patient outcomes, are explored. The article also addresses limitations and safety considerations to provide a comprehensive understanding of hyaluronidase in the context of filler complications. By offering insights into the application and effectiveness of hyaluronidase, this article aimed to enhance practitioners' ability to manage HA filler-related issues effectively and ensure optimal results in aesthetic procedures.

Facial Fillers and Surgical Rhinoplasty: Cross-Sectional Study

This study aims to provide an overview of how rhinoplasty surgeons manage patients with previous nonsurgical rhinoplasty and facial fillers. A multicenter international cross-sectional study was conducted in accordance with strengthening the reporting of observational studies in epidemiology (STROBE) guidelines. A survey was distributed to members of the European Academy of Facial Plastic Surgery and associated colleagues, with responses analyzed from surgeons performing over 10 rhinoplasties annually. A total of 171 surgeons from 45 countries participated, with 165 meeting the inclusion criteria. The respondents included ear, nose, and throat (41%), plastic (7%), maxillo-facial (10%), and facial plastic surgeons (23%), averaging 116 rhinoplasties annually and 13 years of experience. Among the surgeons, 74% perform rhinoplasty on patients with prior nasal fillers, typically waiting 21 weeks after filler rhinoplasty before surgery. Additionally, 44% of surgeons remove nasal fillers preoperatively, primarily using hyaluronidase. During surgery, 76% of surgeons remove nasal fillers, and 25% modify their surgical steps for patients with a history of fillers. This study shows that there is no clear consensus in the management of patients with nasal fillers. Surgeons are often unaware of the preoperative existence of nasal and facial fillers, their potential complications, and their management. To address this, guidelines should be established to facilitate the management of the growing number of patients with facial fillers.

Anti-Inflammatory and Antioxidant Effects of (6S,9R)-Vomifoliol from Gaultheria procumbens L.: In Vitro and Ex Vivo Study in Human Immune Cell Models

(6S,9R)-vomifoliol (VO) is a natural norisoprenoid of the megastigmane type derived from Gaultheria procumbens, an aromatic, evergreen shrub whose leaves, fruits, and aerial parts are used in traditional phytotherapy to treat oxidative stress and inflammation-related disorders. The plant is known as a rich source of essential oil and polyphenols. However, the levels of other constituents of G. procumbens, including VO, have yet to be explored. There is also a knowledge gap in the pharmacological potential of VO in the context of inflammation. Therefore, the present study aimed to investigate the accumulation of VO in leaves, stems, and fruits of G. procumbens and to determine its antioxidant and anti-inflammatory effects in non-cellular in vitro and cell-based models of human immune cells ex vivo. The GC-FID-MS (gas chromatography coupled with flame ionisation detector and mass spectrometer) analysis revealed the leaves as the richest source of VO (0.36 mg/g dw of the plant material) compared to other G. procumbens organs. In non-cellular activity tests, VO showed comparable to positive control anti-inflammatory activity against lipoxygenase, with significantly weaker impact on hyaluronidase and cyclooxygenase-2, and no effect on cyclooxygenase-1 isozyme. VO at 5-75 μM revealed a significant and dose-dependent ability to reduce the reactive oxygen species (ROS) level, downregulate the release of pro-inflammatory cytokines [tumour necrosis factor-α (TNF-α), interleukin-8 (IL-8), IL-6, and IL-1β] and tissue-remodelling enzymes (elastase-2, metalloproteinase-9), and up-regulate the secretion of anti-inflammatory cytokine IL-10 in bacterial lipopolysaccharide (LPS)- and N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-stimulated human neutrophils and peripheral blood mononuclear cells (PBMCs) ex vivo. Furthermore, a significant reduction in IL-6, lipoxygenase (LOX), nuclear factor κ-light-chain-enhancer of activated B cells 1 (NF-κB1), and NF-κB2 gene expression in LPS-stimulated peripheral blood lymphocytes was demonstrated by real-time PCR. The cellular safety of VO at 5-75 μM was confirmed by flow cytometry, with the viability of neutrophils and PBMCs after incubation with VO at 93.8-98.4%. The results encourage further studies of VO as a promising non-cytotoxic natural anti-inflammatory agent and support the use of leaves of G. procumbens in the adjuvant treatment of oxidative stress and inflammation-related diseases of affluence.

Biochemical Characterization and Mechanism of Thermostability of the Thermophilic Hyaluronate Lyase TcHly8D

Hyaluronate lyases are widely used in medicine and biochemical engineering and are also applied as a tool enzyme to prepare oligosaccharides with various biological activities. To date, only a few hyaluronate lyases are on sale with poor thermostability. In this study, a PL8 hyaluronate lyase, TcHly8D, was found from Thermasporomyces composti and expressed in Escherichia coli with a maximum yield of 1.77 × 109 U/L (3.14 g/L) in a 5-L bioreactor. The recombinant TcHly8D exhibited a high hyaluronate lyase activity of 5.64 × 105 U/mg and an excellent thermostability with half-lives of 184.9 h at 60 °C. Fifty micrograms of TcHly8D could catalyze 5 g of hyaluronic acid with an oligosaccharide yield of 84.8% in 4 h. The salt bridges, hydrogen bonds, and proline residues, but not disulfide bonds, played important roles in the thermostability of TcHly8D. These findings provide insights into the multifunctional application potential of TcHly8D in agriculture, medicine, and the food industry.

Engineering thermostability of industrial enzymes for enhanced application performance

Thermostability is a key factor for the industrial application of enzymes. This review categorizes enzymes by their applications and discusses the importance of engineering thermostability for practical use. It summarizes fundamental theories and recent advancements in enzyme thermostability modification, including directed evolution, semi-rational design, and rational design. Directed evolution uses high-throughput screening to generate random mutations, while semi-rational design combines hotspot identification with screening. Rational design focuses on key residues to enhance stability by improving rigidity, foldability, and reducing aggregation. The review also covers rational strategies like engineering folding energy, surface charge, machine learning methods, and consensus design, along with tools that support these approaches. Practical examples are critically assessed to highlight the benefits and limitations of these strategies. Finally, the challenges and potential contributions of artificial intelligence in enzyme thermostability engineering are discussed.

Biochemical Characterization of Hyaluronate Lyase CpHly8 from an Intestinal Microorganism Clostridium perfringens G1121

Hyaluronic acid (HA) is an important component of extracellular matrices (ECM) and a linear polysaccharide involved in various physiological and pathological processes within the biological system. Several pathogens exploit HA degradation within the extracellular matrix to facilitate infection. While many intestinal microorganisms play significant roles in HA utilization in the human body, there remains a scarcity of related studies. This paper addressed this gap by screening intestinal microorganisms capable of degrading HA, resulting in the isolation of Clostridium perfringens G1121, which had been demonstrated the ability to degrade HA. Subsequent genome sequencing and analysis of C. perfringens G1121 revealed its utilization of the polysaccharide utilization loci of HA (PULHA), which was obtained by horizontal gene transfer. The PULHA contains a sequence encoding a hyaluronic acid-specific degradation enzyme designated CpHly8, belonging to polysaccharide lyase family 8. The specific activity of CpHly8 towards HA was 142.98 U/mg, with the optimum reaction temperature and pH observed at 50℃ and 6.0, respectively. The final product of HA degradation by CpHly8 was unsaturated hyaluronic acid disaccharide. Moreover, subcutaneous diffusion experiments with trypan blue in mice revealed that CpHly8 effectively promoted subcutaneous diffusion and sustained its effects long-term, suggesting its potential application as an adjunct in drug delivery. Overall, our study enriches our understanding of intestinal microbial degradation of HA, provides new evidence for horizontal gene transfer among intestinal microorganisms, and confirms that CpHly8 is a promising candidate for intestinal microbial hyaluronidase.

Ultrasound evaluation of peripheral intravenous catheter thrombus formation associated with intravenous flucloxacillin administration: A prospective observational pilot study

Purpose

The purpose of this study was to sonographically evaluate whether intravenous (IV) flucloxacillin administration was associated with an increased risk of peripheral intravenous catheter (PIVC) thrombus formation.

Methods

This observational study included participants enrolled as a convenience sample from a larger prospective study of patients with cellulitis receiving IV antibiotics in the emergency department. Point-of-care ultrasound was used to evaluate the PIVCs for thrombus formation after insertion and at specified timepoints after IV administration of antibiotic or saline solution through to discharge. The primary endpoint included the presence and length of the thrombus in proximity of the catheter tip.

Results

Between May 2021 and June 2022, 25 participants were enrolled and received either IV flucloxacillin (n = 10), other IV antibiotics (n = 8) or no IV antibiotics (control; n = 7). PIVC thrombus formation was sonographically detected in 100%, 67% and 17% of patients in flucloxacillin, other and control groups at 6-12 h (flucloxacillin vs. control; P = 0.015), with a mean length of 17.4 ± 8.1 (flucloxacillin vs. control; P = 0.46), 15.5 ± 13.4 (other vs. control; P = 0.73) and 7.3 ± 17.9 mm (control), respectively. Thrombus formation increased significantly in the flucloxacillin group over time (0->12 h; P = 0.03) but did not increase in the other or control groups.

Discussion

The administration of IV flucloxacillin appears to promote the formation of a PIVC thrombus visible on ultrasound, but the clinical implications are uncertain. Although the vast majority appear to be asymptomatic, they have the potential to become a precursor to thrombophlebitis and lead to early PIVC failure.

Conclusions

It was feasible to identify and measure PIVC thrombus sonographically. Ultrasound showed that IV flucloxacillin administration appeared to be associated with more frequent formation of PIVC thrombus, with these increasing in length over time. Further research is required to confirm these findings in larger studies and to identify any clinical implications of the findings.

How Should We Use Hyaluronidase for Dissolving Hyaluronic Acid Fillers?

BACKGROUND

Hyaluronic acid (HA) fillers are commonly used in esthetic medicine for facial contouring and rejuvenation. However, complications such as overcorrection, vascular occlusion, and irregular filler distribution necessitate the use of hyaluronidase to dissolve the fillers. This study aimed to evaluate the efficacy of hyaluronidase in degrading different types of HA fillers and provide clinical guidelines for its use based on filler type, dosage, and application techniques.

METHODS

A series of in vitro and in vivo experiments were conducted to assess the dissolution of biphasic and monophasic HA fillers using varying concentrations of hyaluronidase. The in vivo component used animal models to determine the duration of hyaluronidase activity in biological tissues, whereas the in vitro study examined the dissolution rates of HA fillers in response to different hyaluronidase concentrations and application methods. A control study using saline was also performed to compare the natural hydration process of the fillers.

RESULTS

Hyaluronidase efficacy was found to vary based on the type of HA filler and the enzyme's concentration. Biphasic fillers dissolved more rapidly at lower concentrations of hyaluronidase compared to monophasic fillers, which required higher concentrations and longer exposure times for effective breakdown. The study also demonstrated that direct injection of hyaluronidase into the filler mass was more effective than surface application. Pharmacokinetic analysis revealed that hyaluronidase activity diminished within 30 min in biological tissues, highlighting the need for timely intervention in clinical scenarios.

CONCLUSION

Hyaluronidase is effective in dissolving HA fillers, with its efficacy dependent on the type of filler, concentration, and application technique. Biphasic fillers respond more quickly to hyaluronidase, whereas monophasic fillers require higher doses and multiple treatments. Clinical recommendations include using direct injection techniques, tailoring hyaluronidase dosage based on the filler type, and considering hypersensitivity reactions. Future research should focus on the long-term effects of hyaluronidase and refining clinical protocols for its use.

Cryo-EM Structure of Human Hyaluronidase PH-20

PH-20 is a specific type of hyaluronidase that plays a critical role in the fertilization process by facilitating the initial binding of sperm to the glycoprotein layer surrounding the oocyte and subsequently breaking down hyaluronic acid polymers in the cumulus cell layer. PH-20 contains an epidermal growth factor (EGF)-like domain, which may be involved in the recognition of the glycoprotein layer in addition to the catalytic domain. Herein, we report the structure of human PH-20 determined by cryogenic electron microscopy. Comparative analyses of the PH-20 structure with two other available hyaluronidase structures reveal a general similarity in the central catalytic domains, including the conservation of catalytically essential residues at the equivalent spatial positions. However, unique difference is found in the EGF-like domain, characterized by a longer sequence that is likely to form a flexibly anchored β-hairpin containing a disulfide bond.

Treatment of the Temples: Brazilian Consensus

INTRODUCTION

The temporal region is emblematic and challenging due to its structural and volumetric changes during aging, which significantly affect facial aesthetics. Despite the importance of addressing temporal aging, many injectors hesitate due to the region's anatomical complexity and risk of complications. This consensus aimed to provide expert guidance on the safest and most effective treatment strategies for the temple.

METHODOLOGY

Twelve Brazilian dermatologists and plastic surgeons with expertise in cosmiatry participated in a survey of 54 objective and one open-ended question to identify best practices. The results were analyzed for consensus, with agreement categorized as a simple majority (50-75%), consensus (> 75%), or strong consensus (> 95%).

RESULTS

Participants agreed that volumization (100%), lifting (90%), and restructuring (82%) are essential for temporal rejuvenation. Hyaluronic acid (HA) was the preferred product for volumization and structuring, with the subcutaneous plane identified as the best option for both. There was no consensus on the product for lifting, though 45.5% favored poly-L-lactic acid (PLLA). Biostimulants such as PLLA and calcium hydroxyapatite were commonly used, with specific dilution strategies. Complications reported included hematomas and nodules, particularly with HA and PLLA.

CONCLUSION

The consensus emphasized the importance of anatomical knowledge and product selection in achieving safe and long-lasting results in temporal rejuvenation. It provided clear recommendations for injection techniques and product choices, advocating for subcutaneous plane treatments for beginners. The findings highlight the need for expert-driven approaches to reduce the risk of complications and optimize patient outcomes in this sensitive region.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Production of Vespa tropica Hyaluronidase by Pichia pastoris

Hyaluronidases have been a subject of great interest in medical and cosmeceutical applications. Previously, our group demonstrated that the venom glands of Vespa tropica contain hyaluronidase enzymes (VesT2s), and heterologous expression of the corresponding gene (VesT2a) in E. coli systems results in inclusion bodies, necessitating functional folding using urea. Here, we report the successful heterologous expression of VesT2a in the Pichia pastoris expression system, with gene construction achieved using GoldenPiCS. After confirming gene integration in the yeast genome, methanol-induced cultures yielded an exceptional amount of VesT2a, approximately two-fold higher than that obtained with the constitutive expression vector (PGAP). Upon culturing in a bioreactor, yeast cells harboring pAOX1-αMF-VesT2a produced secreted proteins with a total yield of 96.45 mg/L. The secreted VesT2a has a molecular weight of 59.35 kDa, significantly higher than the expected molecular weight (~40.05 kDa), presumably due to endogenous glycosylation by the yeast cells. It exhibits optimal activity at 37 °C and pH 3, showing a specific activity of 4238.37 U/mg, and remains active across a broad range of pH and temperature. Notably, it exhibits higher hyaluronidase activity than the crude venom and E. coli-expressed protein, likely due to improved folding via endogenous post-translational modifications, such as disulfide bonds and N-glycosylation; this underscores the potential of heterologous systems for producing venomous hyaluronidases from other species. In silico docking-based analyses further support its catalytic activity and provide insights into seeking natural inhibitors from phenolic-rich plant extracts to alleviate symptoms in patients suffering from insect bites and stings.

Antidiabetic Potential of Black Elderberry Cultivars Flower Extracts: Phytochemical Profile and Enzyme Inhibition

Black elderberry (Sambucus nigra L.) flowers are rich in polyphenolic compounds, including chlorogenic acid and quercetin derivatives, which are known for their health benefits, particularly their antioxidant and antidiabetic properties. This study aimed to optimize the extraction conditions using the Box-Behnken model to maximize polyphenol yields from different elderberry flower cultivars and to evaluate their potential for antidiabetic action. The extracts were analyzed for their phytochemical content and assessed for enzyme inhibition, specifically targeting enzymes critical in carbohydrate digestion and glucose regulation. The anti-inflammatory activity was also assessed. Results indicated that the Black Beauty, Obelisk, and Haschberg cultivars demonstrated significant inhibition of α-glucosidase, with a high inhibitory potential against α-amylase enzymes for the Obelisk cultivar. Additionally, high chlorogenic acid content was strongly correlated with enzyme inhibition and antioxidant activity, suggesting its substantial role in glucose regulation. This study underscores the potential of elderberry flower extracts, particularly those rich in chlorogenic acid, as natural agents for managing blood glucose levels, warranting further exploration of their use in antidiabetic applications.

Antivenom potential of the latex of Jatropha mutabilis baill. (Euphorbiaceae) against Tityus stigmurus venom: Evaluating its ability to neutralize toxins and local effects in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Species of the Jatropha genus (Euphorbiaceae) are used indiscriminately in traditional medicine to treat accidents involving venomous animals. Jatropha mutabilis Baill., popularly known as "pinhão-de-seda," is found in the semi-arid region of Northeastern Brazil. It is widely used as a vermifuge, depurative, laxative, and antivenom.

AIM OF THE STUDY

Obtaining the phytochemical profile of the latex of Jatropha mutabilis (JmLa) and evaluate its acute oral toxicity and inhibitory effects against the venom of the scorpion Tityus stigmurus (TstiV).

MATERIALS AND METHODS

The latex of J. mutabilis (JmLa) was obtained through in situ incisions in the stem and characterized using HPLC-ESI-QToF-MS. Acute oral toxicity was investigated in mice. The protein profile of T. stigmurus venom was obtained by electrophoresis. The ability of latex to interact with venom components (TstiV) was assessed using SDS-PAGE, UV-Vis scanning spectrum, and the neutralization of fibrinogenolytic and hyaluronidase activities. Additionally, the latex was evaluated in vivo for its ability to inhibit local edematogenic and nociceptive effects induced by the venom.

RESULTS

The phytochemical profile of the latex revealed the presence of 75 compounds, including cyclic peptides, glycosides, phenolic compounds, alkaloids, coumarins, and terpenoids, among others. No signs of acute toxicity were observed at a dose of 2000 mg/kg (p.o.). The latex interacted with the protein profile of TstiV, inhibiting the venom's fibrinogenolytic and hyaluronidase activities by 100%. Additionally, the latex was able to mitigate local envenomation effects, reducing nociception by up to 56.5% and edema by up to 50% compared to the negative control group.

CONCLUSIONS

The latex of Jatropha mutabilis exhibits a diverse phytochemical composition, containing numerous classes of metabolites. It does not present acute toxic effects in mice and has the ability to inhibit the enzymatic effects of Tityus stigmurus venom in vitro. Additionally, it reduces nociception and edema in vivo. These findings corroborate popular reports regarding the antivenom activity of this plant and indicate that the latex has potential for treating scorpionism.

LC-ESI-UHR-QqTOF-MS/MS profiling and anti-inflammatory potential of the cultivated Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. fruits from the Algerian region

Opuntia plants are abundant but still underexplored edible resources of the Algerian region. This work chemically characterizes extracts of different parts of the fruit of the commercial Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. growing in Bejaia, and evaluates their anti-inflammatory potential through different cell and cell-free bioassays. The LC-ESI-UHR-QqTOF-MS/MS analysis enabled the identification of 18 compounds, with azelaic acid and 1-O-vanilloyl-β-d-glucose reported here for the first time. Aqueous extracts of seeds were the most effective in scavenging superoxide anion radical (IC50 = 111.08 μg/mL) and presented the best anti-inflammatory potential in LPS-stimulated macrophages (IC50 = 206.30 μg/mL). The pulp of O. stricta suggested potential for addressing post-inflammatory hyperpigmentation, with piscidic and eucomic acids predicted with the strongest binding affinity towards tyrosinase, exhibiting higher scoring values than the reference inhibitor kojic acid. This pioneer study brings valuable perspectives for the pharmacological, nutritional and economic valorization of the wild O. stricta for functional foods.

Engineering protein translocation and unfolded protein response enhanced human PH-20 secretion in Pichia pastoris

Hyaluronidases catalyze the degradation of hyaluronan (HA), which is finding rising applications in medicine, cosmetic, and food industries. Recombinant expression of hyaluronidases in microbial hosts has been given special attention as a sustainable way to substitute animal tissue-derived hyaluronidases. In this study, we focused on optimizing the secretion of hyaluronidase from Homo sapiens in Pichia pastoris by secretion pathway engineering. The recombinant hyaluronidase was first expressed under the control of a constitutive promoter PGCW14. Then, two endoplasmic reticulum-related secretory pathways were engineered to improve the secretion capability of the recombinant strain. Signal peptide optimization suggested redirecting the protein into co-translational translocation using the ost1-proα signal sequence improved the secretion level by 20%. Enhancing the co-translational translocation by overexpressing signal recognition particle components further enhanced the secretory capability by 48%. Then, activating the unfolded protein response by overexpressing a transcriptional factor ScHac1p led to a secreted hyaluronidase activity of 4.06 U/mL, which was 2.1-fold higher than the original strain. Finally, fed-batch fermentation elevated the production to 19.82 U/mL. The combined engineering strategy described here could be applied to enhance the secretion capability of other proteins in yeast hosts. KEY POINTS: • Improving protein secretion by enhancing co-translational translocation in P. pastoris was reported for the first time. • Overexpressing Hac1p homologous from different origins improved the rhPH-20 secretion. • A 4.9-fold increase in rhPH-20 secretion was achieved after fermentation optimization and fed-batch fermentation.

Preparation and Rheological Evaluation of Thiol-Maleimide/Thiol-Thiol Double Self-Crosslinking Hyaluronic Acid-Based Hydrogels as Dermal Fillers for Aesthetic Medicine

This study presents the development of thiol-maleimide/thiol-thiol double self-crosslinking hyaluronic acid-based (dscHA) hydrogels for use as dermal fillers. Hyaluronic acid with varying degrees of maleimide substitution (10%, 20%, and 30%) was synthesized and characterized, and dscHA hydrogels were fabricated using two molecular weights of four-arm polyethylene glycol (PEG10K/20K)-thiol as crosslinkers. The six resulting dscHA hydrogels demonstrated solid-like behavior with distinct physical and rheological properties. SEM analysis revealed a decrease in porosity with higher crosslinker MW and maleimide substitution. The swelling ratios of the six hydrogels reached equilibrium at approximately 1 h and ranged from 20% to 35%, indicating relatively low swelling. Degradation rates decreased with increasing maleimide substitution, while crosslinker MW had little effect. Higher maleimide substitution also required greater injection force. Elastic modulus (G') in the linear viscoelastic region increased with maleimide substitution and crosslinker MW, indicating enhanced firmness. All hydrogels displayed similar creep-recovery behavior, showing instantaneous deformation under constant stress. Alternate-step strain tests indicated that all six dscHA hydrogels could maintain elasticity, allowing them to integrate with the surrounding tissue via viscous deformation caused by the stress exerted by changes in facial expression. Ultimately, the connection between the clinical performance of the obtained dscHA hydrogels used as dermal filler and their physicochemical and rheological properties was discussed to aid clinicians in the selection of the most appropriate hydrogel for facial rejuvenation. While these findings are promising, further studies are required to assess irritation, toxicity, and in vivo degradation before clinical use. Overall, it was concluded that all six dscHA hydrogels show promise as dermal fillers for various facial regions.

Combined Application of Hyaluronidase and Collagenase for Late-Onset Edema in Periocular Area After Hyaluronic Acid Volume Repositioning: A Six-Case Retrospective Review

BACKGROUND AND OBJECTIVE

Although generally low-risk, hyaluronic acid (HA) dermal fillers can lead to late-onset edema, particularly in the periocular region. This condition typically manifests three to four months post-injection and requires specialized management, usually with hyaluronidase. However, increased use of hyaluronidase has resulted in instances of post-hyaluronidase syndrome, leading to unaesthetic outcomes. This study presents a retrospective case series that utilizes a novel technique combining two enzymes to improve late-onset edema and prevent post-hyaluronidase syndrome development.

METHODS

From 2019 to 2024, six patients in our aesthetic clinic received a novel therapeutic approach involving co-administration of 1,500 IU of hyaluronidase and collagenase with a cannula to address late-onset edema in the periocular area.

RESULTS

The combination of high-dose hyaluronidase and low-dose collagenase improved late-onset edema in all patients after a single treatment. Statistical analysis showed a significant improvement in aesthetic scores (P < 0.05), with effect sizes of 0.89 for Hirmand, 1.3 for the Teoxane Infraorbital Hollows Scale (TIOHS), and 1.2 for O'Mahoney's photo-numeric scale. No post-hyaluronidase syndrome or complications were observed.

CONCLUSIONS

This combined technique utilizing 1,500 IU of hyaluronidase and collagenase GH PB220 from Pbserum (Madrid, Spain) effectively achieves significant aesthetic improvements with a high safety profile, offering a promising alternative for managing late-onset edema after HA dermal filler treatments.

Excipient-free nanotransformation of hydrophilic macromolecules using aqueous counter collision for enhanced bioavailability

The demand for sustainable, eco-friendly biopolymer transdermal delivery systems has increased owing to growing environmental awareness. In this study, we used aqueous counter collision (ACC), a nontoxic nanotransformation method, to convert high- and ultrahigh-molecular-weight hydrophilic macromolecules into their corresponding nanoparticles (NPs). Hyaluronic acid (HA) and crosslinked HA (CLHA) were chosen as the model compounds. Their NPs exhibited particle sizes in the range of 10-100 nm and negative zeta potentials (-20 to -30 mV). Transmission electron microscopy revealed that the NPs were nearly spherical with smooth surfaces. Fourier-transform infrared and proton nuclear magnetic resonance spectroscopy and agarose gel electrophoresis confirmed that the structures and molecular weights of HA and CLHA remained unaltered after ACC. However, the storage and loss moduli of HANPs and CLHANPs were significantly lower than those of HA and CLHA, respectively. Furthermore, the permeation of HANPs and CLHANPs in reconstructed human skin and human cadaver skin was visualized and quantified. HANPs and CLHANPs penetrated deeper into the skin, whereas HA and CLHA were mainly found in the stratum corneum. The total skin absorption (permeation and deposition) of HANPs and CLHANPs was approximately 2.952 and 5.572 times those of HA and CLHA, respectively. Furthermore, HANPs and CLHANPs exhibited resistance to enzyme and free radical degradation. Our findings reveal ACC as a promising, sustainable hydrophilic macromolecule delivery system compared with the chemical hydrolysis of HA.

Improved lymphangiogenesis around vascularized lymph node flaps by periodic injection of hyaluronidase in a rodent model

Vascularized lymph node transfer (VLNT) is an advanced surgical approach for secondary lymphedema (SLE) treatment, but tissue fibrosis around the lymph node flap (VLNF) inhibiting lymphangiogenesis is the biggest challenge undermining its therapeutic efficacy. This study explored the effects of periodic hyaluronidase (HLD) injection in reducing fibrosis and promoting lymphangiogenesis in 52 Sprague-Dawley rats with a VLNF over 13 weeks. The results demonstrated that HLD administration significantly enhanced swelling reduction, lymphatic drainage efficiency, and lymphatic vessel regeneration, with up to a 26% decrease in tissue fibrosis around the VLNF. These findings suggest that combining VLNT with periodic injections of HLD could substantially improve SLE treatment outcomes in clinical settings. It offers a promising direction for future therapeutic strategies and drug development aimed at increasing the efficacy of surgical treatment for SLE patients.

Resolve and dissolve-An ultrasound-guided investigation on the effects of hyaluronidase on different soft tissue fillers

BACKGROUND

Nonsurgical cosmetic procedures, particularly the use of hyaluronic acid (HA)-based soft tissue fillers, are becoming increasingly popular. This trend has catalyzed the development of a plethora of HA-based products differing in product characteristics, thereby catering to an ever-widening spectrum of aesthetic applications. However, complications rise concomitant with the increasing number of procedures. Among the strategies to manage such adverse events is the enzymatic breakdown with hyaluronidase.

OBJECTIVE

To analyze the response of different HA-based soft tissue filler materials to hyaluronidase injections.

METHODS

A total of 11 different HA-based soft tissue fillers were evaluated using noninvasive ultrasound imaging to assess their behavior in response to hyaluronidase injections. The HA-based soft tissue fillers were categorized according to their product characteristics into a structuring, volumizing, and lip volumizing group. Standardized injections of 0.2 cc were performed in chicken breast to simulate human tissue. Ultrasound measurements of width, height, and calculated volume were performed immediately after filler injection, 1 h and 24 h following hyaluronidase injection.

RESULTS

Regardless of the soft tissue filler analyzed, the most significant volume reduction occurred within the first h after applying hyaluronidase, with a 64.1% decrease from the initial volume. After 24 h, the total volume reduction reached 81.7%. No statistically significant differences were found when comparing the three groups at each follow-up time period, except for the height measurement after 1 h. While width was statistically significant in all groups between the investigated follow-up groups, the volume reduction was only statistically significant in the groups with the highest and second highest G' values (i.e., Group 1-structuring, Group 2-volumizing).

CONCLUSION

The effectiveness of hyaluronidase in dissolving HA-based fillers is initially independent of product characteristics of HA-based fillers such as G-prime, with increased efficacy in fillers with higher G-prime values, as evidenced by significant volume reductions in such groups.

Utility of Authentic 13C-Labeled Disaccharide to Calibrate Hyaluronan Content Measurements by LC-MS

Hyaluronan (hyaluronic acid, HA), a key glycosaminoglycan in the extracellular matrix, plays crucial roles in various physiological and pathological processes, including development, tissue hydration, inflammation, and tumor progression. Traditional methods for HA quantification, such as ELISA-like assays, often have limitations in sensitivity and specificity, particularly for lower molecular weight HA. In this work, we introduce a coupled liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method that employs a chemoenzymatically synthesized 13C-labeled lyase-derived authentic HA disaccharide calibrant for quantification of HA at the nanogram level. The method was validated against three HA polysaccharides with the sizes of ~33, 210, and 540 kDa. We applied this quantification technique to mouse tissues and plasma from both healthy and acetaminophen-induced acute liver injury mice. Our data revealed a ~75-fold increase in HA concentration in the liver of acetaminophen-injured mice with a concomitant depletion from plasma. Overall, our method offers a robust, universal, and highly sensitive tool for HA analysis in diverse biological samples that will advance the investigation of the roles of this polysaccharide in human disease conditions.

Hyaluronidase overcomes the extracellular matrix barrier to enhance local drug delivery

The stratum corneum of the skin presents the initial barrier to transdermal penetration. The dense structure of the extracellular matrix (ECM) further impedes local drug dispersion. Hyaluronidase (HAase) is a key component for the degradation of glycosidic bonding sites in hyaluronic acid (HA) within the ECM to overcome this barrier and enhance drug dispersion. HAase activity is optimal at 37-45 °C and in the pH range 4.5-5.5. Numerous FDA-approved formulations are available for the clinical treatment of extravasation and other diseases. HAase combined with various new nanoformulations can markedly improve intradermal dispersion. By degrading HA to create tiny channels that reduce the ECM density, these small nanoformulations then use these channels to deliver drugs to deeper layers of the skin. This deep penetration may increase local drug concentration or facilitate penetration into the blood or lymphatic circulation. Based on the generalization of 114 studies from 2010 to 2024, this article summarizes the most recent strategies to overcome the HAase-based ECM barrier for local drug delivery, discusses opportunities and challenges in clinical applications, and provides references for the future development of HAase. In the future, HAase-assisted topical administration is necessary to achieve systemic effects and to standardize HAase application protocols.

Cloning, expression and characterization of novel hyaluronan lyases Vhylzx1 and Vhylzx2 from Vibrio sp. ZG1

Hyaluronidases are a class of enzymes that can degrade hyaluronic acid and have a wide range of applications in the medical field. In this study, the marine bacterium Vibrio sp. ZG1, which can degrade HA, was isolated, leading to the discovery of two novel hyaluronan lyases, Vhylzx1 and Vhylzx2, through genome sequencing and bioinformatic analysis. These lyases belong to the polysaccharide lyase-8 family. Vhylzx1 and Vhylzx2 specifically degrade HA, with highest activity at 35 °C, pH 5.7 and 50 °C, pH 7.1. Vhylzx1 and Vhylzx2 are endo-type enzymes that can fully degrade HA into unsaturated disaccharides. Sequence homology assessment and site-directed mutagenesis revealed that the catalytic residues of Vhylzx1 are Asn231, His281, and Tyr290, and that the catalytic residues of Vhylzx2 are Asn227, His277, and Tyr286. Moreover, this study used consensus sequences to enhance the specific activity of Vhylzx2 mutants. Notably, the mutants V564I, N742D, L619F, and D658G increases the specific activity by 2.4, 2.2, 1.3, and 1.2-fold. These characteristics are useful for further basic research and applications, and have a promising application in the preparation of biologically active hyaluronic acid oligosaccharides.

Ethyl Acetate Fraction from Eleutherococcus divaricatus Root Extract as a Promising Source of Compounds with Anti-Hyaluronidase, Anti-Tyrosinase, and Antioxidant Activity but Not Anti-Melanoma Activity

Eleutherococcus divaricatus (Siebold and Zucc.) S. Y. Hu. has been used in Traditional Chinese Medicine (TCM) due to its anticancer, immunostimulant, and anti-inflammatory activities. However, its mechanism of action and chemical composition are still insufficiently understood and require more advanced research, especially for cases in which anti-inflammatory properties are beneficial. The aim of this study was to evaluate the impact of E. divaricatus root extracts and fractions on proinflammatory serum hyaluronidase and tyrosinase in children diagnosed with acute lymphoblastic leukemia. Antioxidant and anti-melanoma activities were also examined and correlated with metabolomic data. For the first time, we discovered that the ethyl acetate fraction significantly inhibits hyaluronidase activity, with mean group values of 55.82% and 63.8% for aescin used as a control. However, interestingly, the fraction showed no activity against human tyrosinase, and in A375 melanoma cells treated with a doxorubicin fraction, doxorubicin activity decreased. This fraction exhibited the most potent antioxidant activity, which can be attributed to high contents of polyphenols, especially caffeic acid (24 mg/g). The findings suggest an important role of the ethyl acetate fraction in hyaluronidase inhibition, which may additionally indicate its anti-inflammatory property. The results suggest that this fraction can be used in inflammatory-related diseases, although with precautions in cases of patients undergoing chemotherapy.

Adverse Effects Associated with Dermal Filler Treatments: Part II Vascular Complication

Vascular complications arising from dermal filler treatments pose significant risks, including ischemia, tissue necrosis, and severe outcomes like blindness and pulmonary embolism. This study investigates the mechanisms of vascular complications, categorizing them into extravascular compression and intravascular emboli. Extravascular compression occurs when injected fillers compress adjacent blood vessels, leading to ischemia and potential necrosis, while intravascular emboli result from fillers entering blood vessels, causing blockages. The study emphasizes the importance of anatomical knowledge, careful injection techniques, and early intervention. Management strategies include the use of hyaluronidase to dissolve HA fillers, vasodilators to improve blood circulation, and hyperbaric oxygen therapy. The regions most susceptible to complications align with major arterial pathways, particularly the nasolabial folds and nasal region. The study also highlights the need for meticulous injection techniques, the use of cannulas over needles in high-risk areas, and the aspiration test to detect vessel penetration. Early detection and immediate intervention are crucial to mitigate adverse outcomes. Continuous education and training for practitioners, along with advancements in filler materials and injection methods, are essential for improving the safety of cosmetic procedures. This comprehensive understanding aids in preventing and managing vascular complications, ensuring better patient outcomes. The field of dermal filler treatments is advancing with new techniques and technologies, such as High-Resolution Ultrasound, Infrared Imaging, self-crossing hyaluronic acid filler, biodegradable microspheres, and microinjection.

Purification and characterization of the produced hyaluronidase by Brucella Intermedia MEFS for antioxidant and anticancer applications

Hyaluronidase (hyase) is an endoglycosidase enzyme that degrades hyaluronic acid (HA) and is mostly known to be found in the extracellular matrix of connective tissues. In the current study, eleven bacteria isolates and one actinomycete were isolated from a roaster comb and screened for hyase production. Seven isolates were positive for hyase, and the most potent isolate was selected based on the diameter of the transparent zone. Based on the morphological, physiological, and 16 S rRNA characteristics, the most potent isolate was identified as Brucella intermedia MEFS with accession number OR794010. The environmental conditions supporting the maximum production of hyase were optimized to be incubation at 30 ºC for 48 h and pH 7, which caused a 1.17-fold increase in hyase production with an activity of 84 U/mL. Hyase was purified using a standard protocol, including precipitation with ammonium sulphate, DEAE as ion exchange chromatography, and size exclusion chromatography using Sephacryle S100, with a specific activity of 9.3-fold compared with the crude enzyme. The results revealed that the molecular weight of hyase was 65 KDa, and the optimum conditions for hyase activity were at pH 7.0 and 37 °C for 30 min. The purified hyase showed potent anticancer activities against colon, lung, skin, and breast cancer cell lines with low toxicity against normal somatic cells. The cell viability of hyase-treated cancer cells was found to be in a dose dependent manner. Hyase also controlled the growth factor-induced cell cycle progression of breast cancer cells and caused relative changes in angiogenesis-related genes as well as suppressed many pro-inflammatory proteins in MDA cells compared with 5-fluorouracil, indicating the significant role of hyase as an anticancer agent. In addition, hyase recorded the highest DPPH scavenging activity of 65.49% and total antioxidant activity of 71.84% at a concentration of 200 µg/mL.

Injectable Penile Enhancement Procedures: A Review of Agents, Risks, and Complications

Penile dysmorphophobic disorder describes men who feel their normal penile size is inadequate. Penile fillers have been used to address penile size dissatisfaction. However, unpredictability of these procedures can yield unfavorable outcomes. Reactions to these foreign bodies are inherently uncertain, owing to an array of materials, concentrations, and biocompatibility. Management of complications also varies. As fillers are more commonly used in cosmetic procedures to augment facial features, most genitourinary surgeons are unfamiliar with these therapies. This review seeks to describe the available materials, techniques, and risk profiles of the various types of fillers used for penile augmentation.

Static and Dynamic Filler-Associated Tear Trough Deformities: Manifestations and Treatment Algorithm

BACKGROUND

Fillers are popular substances for the correction of tear trough deformity. Despite well-documented complications increasing gradually, standardized treatment algorithm for deformity secondary to improper injection is still limited.

METHODS

Between April 2020 and April 2023, a total of 22 patients with filler-associated tear trough deformity with static bulges or dynamic swells after injection of tear trough were enrolled. For patients who received hyaluronic acid (HA) and unknown fillers, hyaluronidase dissolution was performed. For patients who received non-HA fillers and unknown fillers that failed to dissolve, a magnetic resonance imaging (MRI) examination was conducted. Surgical approaches were selected based on the filler distribution and the condition of the lower eyelid. Ligament releasement and fat transposition were accomplished when fillers were excised. Aesthetic outcomes were evaluated by double-blind examiners using the Global Aesthetic Improvement Scale after patients were followed up.

RESULTS

In total, the study included 3 patients with simple static deformities, 1 patient with simple dynamic, and 18 patients with both. Fourteen patients underwent transconjunctival surgery and 8 patients underwent transcutaneous surgery, among which 18 patients underwent hyaluronidase dissolution and 8 patients underwent MRI prior to surgery. A total of 4 patients with self-limited complications recovered after conservative treatment. 90.9% of patients expressed satisfaction or high satisfaction with the treatment results.

CONCLUSION

Filler-associated tear trough deformities could be classified into static and dynamic deformities, which could appear separately or simultaneously. Treatment of deformities should be based on characteristics of fillers, in which MRI could serve as a promising tool.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Acyclovir extravasation in a newborn: a case report

OBJECTIVE

Extravasation of infused drugs is not a rare problem in medical practice. Acyclovir is a vesicant and an antiviral medication commonly used for young children. In the present study, we presented a neonate with soft tissue damage due to acyclovir extravasation.

CASE REPORT

A female newborn (Iranian, Asian) with gestational age 37+2 weeks and breech presentation was born by Cesarean delivery from a mother with a recent history of Herpes simplex virus (HSV) infection (Yas Women's Hospital, Tehran, Iran). Intravenous administration of acyclovir was initiated through a peripheral catheter inserted on the dorsal side of the left hand. A few minutes after the second dose, the patient showed a diffused firm swelling, local discoloration, and induration in the dorsum of the hand. The peripheral catheter was removed immediately. Hyaluronidase was injected subcutaneously in five different regions around the catheterization site. Intermittent limb elevation and cold compression (for 10 minutes) were applied. Serial follow-ups and examinations were performed hourly to check limb inflammation, ischemia, and compartment syndrome. The limb swelling and discoloration significantly improved 4 hours after the second dose of hyaluronidase.

CONCLUSION

Early diagnosis of acyclovir extravasation and immediate management could prevent severe complications in neonates. Further studies are needed to suggest a standard approach and treatment protocol for acyclovir extravasation.

Phenytoin Induced Purple Glove Syndrome: An Effective Management Technique

Background: Purple glove syndrome (PGS) is a rare condition characterized by limb edema, discoloration, and pain associated with intravenous and oral phenytoin administration. The pathophysiology is poorly understood, and there is no established treatment. Simple cases have previously been managed with hyaluronidase subcutaneous injections, with more severe cases resulting in compartment syndrome, debridement, or even amputation. Methods/Results: In this case report, a 2-year-old boy with status epilepticus developed PGS after receiving intravenous phenytoin via a cannula on the dorsum of the right hand. The patient was successfully managed by locally infiltrating subcutaneous hyaluronidase diffusely to the affected area, titrating its dose to effect, rather than aiming to adhere to any specific dosing limitation. The child was reviewed daily by the Plastic Surgery team until being discharged, and focal lesions began to demarcate after 48 hours, with epidermal loss but no deeper trauma. The epidermis peeled within one month, with healthy underlying skin found underlying when followed up in clinic. Conclusions: This case illustrates that subcutaneous administration of hyaluronidase and titrating to effect provides an effective and safe treatment for treating distal cases of early PGS in children.

Contribution of staphylococcal virulence factors in the pathogenesis of thrombosis

Staphylococci are responsible for many infections in humans, starting with skin and soft tissue infections and finishing with invasive diseases such as endocarditis, sepsis and pneumonia, which lead to high mortality. Patients with sepsis often demonstrate activated clotting pathways, decreased levels of anticoagulants, decreased fibrinolysis, activated endothelial surfaces and activated platelets. This results in disseminated intravascular coagulation and formation of a microthrombus, which can lead to a multiorgan failure. This review describes various staphylococcal virulence factors that contribute to vascular thrombosis, including deep vein thrombosis in infected patients. The article presents mechanisms of action of different factors released by bacteria in various host defense lines, which in turn can lead to formation of blood clots in the vessels.

Hyaluronan-based hydrogel delivering glucose to mesenchymal stem cells intended to treat osteoarthritis

Mesenchymal stem cell (MSC) therapy shows promise in regenerative medicine. For osteoarthritis (OA), MSCs delivered to the joint have a temporal window in which they can secrete growth factors and extracellular matrix molecules, contributing to cartilage regeneration and cell proliferation. However, upon injection in the non-vascularized joint, MSCs lacking energy supply, starve and die too quickly to efficiently deliver enough of these factors. To feed injected MSCs, we developed a hyaluronic acid (HA) derivative, where glucose is covalently bound to hyaluronic acid. To achieve this, the glucose moiety in 4-aminophenyl-β-D-glucopyranoside was linked to the HA backbone through amidation. The hydrogel was able to deliver glucose in a controlled manner using a trigger system based on hydrolysis catalyzed by endogenous ß-glucosidase. This led to glucose release from the hyaluronic acid backbone inside the cell. Indeed, our hydrogel proved to rescue starvation and cell mortality in a glucose-free medium. Our approach of adding a nutrient to the polymer backbone in hydrogels opens new avenues to deliver stem cells in poorly vascularized, nutrient-deficient environments, such as osteoarthritic joints, and for other regenerative therapies.

Endothelial PDGF-D contributes to neurovascular protection after ischemic stroke by rescuing pericyte functions

Ischemic stroke induces neovascularization of the injured tissue as an attempt to promote structural repair and neurological recovery. Angiogenesis is regulated by pericytes that potently react to ischemic stroke stressors, ranging from death to dysfunction. Platelet-derived growth factor (PDGF) receptor (PDGFR)β controls pericyte survival, migration, and interaction with brain endothelial cells. PDGF-D a specific ligand of PDGFRβ is expressed in the brain, yet its regulation and role in ischemic stroke pathobiology remains unexplored. Using experimental ischemic stroke mouse model, we found that PDGF-D is transiently induced in brain endothelial cells at the injury site in the subacute phase. To investigate the biological significance of PDGF-D post-ischemic stroke regulation, its subacute expression was either downregulated using siRNA or upregulated using an active recombinant form. Attenuation of PDGF-D subacute induction exacerbates neuronal loss, impairs microvascular density, alters vascular permeability, and increases microvascular stalling. Increasing PDGF-D subacute bioavailability rescues neuronal survival and improves neurological recovery. PDGF-D subacute enhanced bioavailability promotes stable neovascularization of the injured tissue and improves brain perfusion. Notably, PDGF-D enhanced bioavailability improves pericyte association with brain endothelial cells. Cell-based assays using human brain pericyte and brain endothelial cells exposed to ischemia-like conditions were applied to investigate the underlying mechanisms. PDGF-D stimulation attenuates pericyte loss and fibrotic transition, while increasing the secretion of pro-angiogenic and vascular protective factors. Moreover, PDGF-D stimulates pericyte migration required for optimal endothelial coverage and promotes angiogenesis. Our study unravels new insights into PDGF-D contribution to neurovascular protection after ischemic stroke by rescuing the functions of pericytes.

Endothelial cell dynamics in sepsis-induced acute lung injury and acute respiratory distress syndrome: pathogenesis and therapeutic implications

Sepsis, a prevalent critical condition in clinics, continues to be the leading cause of death from infections and a global healthcare issue. Among the organs susceptible to the harmful effects of sepsis, the lungs are notably the most frequently affected. Consequently, patients with sepsis are predisposed to developing acute lung injury (ALI), and in severe cases, acute respiratory distress syndrome (ARDS). Nevertheless, the precise mechanisms associated with the onset of ALI/ARDS remain elusive. In recent years, there has been a growing emphasis on the role of endothelial cells (ECs), a cell type integral to lung barrier function, and their interactions with various stromal cells in sepsis-induced ALI/ARDS. In this comprehensive review, we summarize the involvement of endothelial cells and their intricate interplay with immune cells and stromal cells, including pulmonary epithelial cells and fibroblasts, in the pathogenesis of sepsis-induced ALI/ARDS, with particular emphasis placed on discussing the several pivotal pathways implicated in this process. Furthermore, we discuss the potential therapeutic interventions for modulating the functions of endothelial cells, their interactions with immune cells and stromal cells, and relevant pathways associated with ALI/ARDS to present a potential therapeutic strategy for managing sepsis and sepsis-induced ALI/ARDS.

Clinical Efficacy in Skin Hydration and Reducing Wrinkles of Nanoemulsions Containing Macadamia integrifolia Seed Oil

This study aimed to assess natural oils for their antioxidant and anti-hyaluronidase properties and select the most effective candidate for development into nanoemulsions (NE) for clinical evaluations. The oils were assessed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) and ferric thiocyanate assays for antioxidant properties and an enzyme-substrate reaction assay for anti-hyaluronidase activity. The most potent oil was formulated into conventional emulsions (CE) and NE, which were characterized and evaluated for their stability, both in accelerated and long-term conditions. The irritation potential was assessed using both the hen's eggs chorioallantoic membrane test and a clinical trial. Skin hydration enhancement and skin wrinkle reduction efficacy were clinically assessed. Macadamia integrifolia oil exhibited significant potency as an ABTS•+ radical scavenger, lipid peroxidation inhibitor, and hyaluronidase inhibitor (p < 0.05). Both the CE and NE, comprising 15% w/w oil, 5% w/w Tween® 80 and Span® 80, and 80% w/w DI water, were found to be optimal. NE with an internal droplet size of 112.4 ± 0.8 nm, polydispersity index of 0.17 ± 0.01, and zeta potential of -31.5 ± 1.0 mV, had good stability and induced no irritation. Both CE and NE enhanced skin hydration and reduced skin wrinkles in human volunteers, while NE was outstanding in skin hydration enhancement.

Madelung's Disease Evolving to Liposarcoma: An Uncommon Encounter

(1) Background: Madelung's disease-known also as Benign Symmetric Adenolipomatosis (BSA) or Multiple Symmetric Lipomatosis (MSL), is a rare subcutaneous tissue disease characterized by the proliferation of non-encapsulated fat tissue with mature adipocytes. Patients develop symmetrical fatty deposits of varying sizes, (located particularly around the neck, shoulders, upper and middle back, arms, abdomen, and thighs), having clinical, esthetic, and psychiatric repercussions. (2) Methods: We report a case diagnosed with BSA upon admission to the Neurological and Internal Medicine Departments of the Emergency Clinical Hospital of Galati. (3) Results: This patient developed compressive phenomena and liposarcoma with liver metastasis, followed by death shortly after hospital presentation. The histopathology examination confirmed right latero-cervical liposarcoma and round cell hepatic metastasis. The specific metabolic ethiopathogenic mechanism has not been elucidated, but the adipocytes of BSA are different from normal cells in proliferation, hormonal regulation, and mitochondrial activity; a rare mitochondrial gene mutation, together with other interacting genetic or non-genetic factors, have been considered in recent studies. A thorough literature search identified only three cases reporting malignant tumors in BSA patients. (4) Conclusions: The goal of our paper is to present this rare case in the oncogenic synergism of two tumors. In the management of this BSA disorder, possible malignant transformation should be considered, although only scarce evidence was found supporting this.

Additive manufacturing of wet-spun chitosan/hyaluronic acid scaffolds for biomedical applications

Additive manufacturing (AM) holds great potential for processing natural polymer hydrogels into 3D scaffolds exploitable for tissue engineering and in vitro tissue modelling. The aim of this research activity was to assess the suitability of computer-aided wet-spinning (CAWS) for AM of hyaluronic acid (HA)/chitosan (Cs) polyelectrolyte complex (PEC) hydrogels. A post-printing treatment based on HA chemical cross-linking via transesterification with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was investigated to enhance the structural stability of the developed scaffolds in physiological conditions. PEC formation and the esterification reaction were investigated by infrared spectroscopy, thermogravimetric analysis, evolved gas analysis-mass spectrometry, and differential scanning calorimetry measurements. In addition, variation of PMVEMA concentration in the cross-linking medium was demonstrated to strongly influence scaffold water uptake and its stability in phosphate buffer saline at 37 °C. The in vitro cytocompatibility of the developed hydrogels was demonstrated by employing the murine embryo fibroblast Balb/3T3 clone A31 cell line, highlighting that PMVEMA cross-linking improved scaffold cell colonization. The results achieved demonstrated that the developed hydrogels represent suitable 3D scaffolds for long term cell culture experiments.

Structural identification and quantification of unreported sialylated N-glycans in bovine testicular hyaluronidase by LC-ESI-HCD-MS/MS

Bovine testicular hyaluronidase (BTH), which accelerates the absorption and dispersion of drugs by decomposing hyaluronan in subcutaneous tissues, has been used in medical applications, including local anesthesia, ophthalmology, and dermatosurgery. The requirement of N-glycans for the activity of human hyaluronidase has been reported, and BTH has greater activity than human hyaluronidase. However, the N-glycan characteristics of BTH are unclear. From a commercial BTH source containing additional proteins, purified BTH (pBTH) was obtained using size exclusion chromatography, and the structures and quantities of its N-glycans were analyzed using liquid chromatography (LC)-electrospray ionization-higher energy collisional dissociation (HCD)-tandem mass spectrometry (MS/MS). In pBTH, 32 N-glycans were identified, with 12 sialylations (39.0% of total N-glycan content), nine core-fucosylations (31.5%), six terminal galactosylations (14.6%), five high-mannosylations (13.7%), and four bisecting N-acetylglucosamine structures (7.8%). The presence of sialylated glycopeptides in pBTH was confirmed by nano-LC-HCD-MS/MS analysis. The absolute quantity of all N-glycans was calculated as 1.4 pmol (0.6 pmol for sialylation) in pBTH (1.0 pmol). The sialylation level (related to half-life, thermal stability, resistance to proteolysis, and solubility) was 24.4 times higher than that of human hyaluronidase. The hyaluronan degradation activity of de-sialylated pBTH decreased to 41.2 ± 4.2%, showing that sialylated N-glycans were required for pBTH activity as well. This is the first study to identify and quantify 32 N-glycans of pBTH and investigate their structural roles in its activity. The presence of larger amounts of sialylated N-glycans in pBTH than in human hyaluronidase suggests a greater utilization of pBTH.

A Scoping Review of Hyaluronidase Use in Managing the Complications of Aesthetic Interventions

BACKGROUND

Hyaluronidase is used as an adjunct or main treatment to manage complications associated with cosmetic hyaluronic acid (HA) filler injections such as necrosis, blindness, hypersensitivity, delayed nodules, and poor aesthetic outcomes.

OBJECTIVE

To systematically map the available evidence and identify the gaps in knowledge on the effectiveness of hyaluronidase use in managing the aesthetic complications associated with HA injections (vascular occlusion, blindness, nodules, delayed hypersensivity, granuloma, poor aesthetic outcome).

METHODS

PubMed, Medline, Embase and Cochrane databases were used up to May 2022, to look for randomized clinical trials (RCTs), clinical trials, and retrospective case-control studies reporting on the use of hyaluronidase for managing the HA filler injection complications.

RESULTS

The database search yielded 395 studies; of those 5 RCTs (all carried out in the USA) were selected (53 subjects), indicating the effectiveness of hyaluronidase for removal of un-complicated injected HA nodules (forearm, upper arm, or back skin). The follow-ups ranged from 14 days to 4 years. The amount of HA filler injected into each site varied from 0.2 to 0.4 mL. A dose dependent response was observed for most HA fillers. No major adverse reactions were reported. Overall, for removal of every 0.1 mL of HA filler they injected 1.25-37.5 units of hyaluronidase (single injections). When 3 consecutive weekly hyaluronidase injection was used much lower doses of 0.375-2.25 unit was utilised. There was no evidence in a form of RCTs, clinical trials, and retrospective case-control studies on the removal/reversal of HA injections in the facial skin, or management of over-corrections, inflammatory nodules, or tissue ischemia/necrosis associated with HA filler injection.

CONCLUSION

Based on studies on the forearm, upper arm and back skin, hyaluronidase can be used for the reversal of uncomplicated HA filler injection nodule. However, further adequately powered studies are warranted to establish the ideal treatment protocol/dose of hyaluronidase for reversal of HA filler injections in the facial region or management of complications associated with aesthetic HA injection.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Methods for the induction of labor: efficacy and safety

This review assessed the efficacy and safety of pharmacologic agents (prostaglandins, oxytocin, mifepristone, hyaluronidase, and nitric oxide donors) and mechanical methods (single- and double-balloon catheters, laminaria, membrane stripping, and amniotomy) and those generally considered under the rubric of complementary medicine (castor oil, nipple stimulation, sexual intercourse, herbal medicine, and acupuncture). A substantial body of published reports, including 2 large network meta-analyses, support the safety and efficacy of misoprostol (PGE1) when used for cervical ripening and labor induction. Misoprostol administered vaginally at doses of 50 μg has the highest probability of achieving vaginal delivery within 24 hours. Regardless of dosing, route, and schedule of administration, when used for cervical ripening and labor induction, prostaglandin E2 seems to have similar efficacy in decreasing cesarean delivery rates. Globally, although oxytocin represents the most widely used pharmacologic agent for labor induction, its effectiveness is highly dependent on parity and cervical status. Oxytocin is more effective than expectant management in inducing labor, and the efficacy of oxytocin is enhanced when combined with amniotomy. However, prostaglandins administered vaginally or intracervically are more effective in inducing labor than oxytocin. A single 200-mg oral tablet of mifepristone seems to represent the lowest effective dose for cervical ripening. The bulk of the literature assessing relaxin suggests this agent has limited benefit when used for this indication. Although intracervical injection of hyaluronidase may cause cervical ripening, the need for intracervical administration has limited the use of this agent. Concerning the vaginal administration of nitric oxide donors, including isosorbide mononitrate, isosorbide, nitroglycerin, and sodium nitroprusside, the higher incidence of side effects with these agents has limited their use. A synthetic hygroscopic cervical dilator has been found to be effective for preinduction cervical ripening. Although a pharmacologic agent may be administered after the use of the synthetic hygroscopic dilator, in an attempt to reduce the interval to vaginal delivery, concomitant use of mechanical and pharmacologic methods is being explored. Combining the use of a single-balloon catheter with dinoprostone, misoprostol, or oxytocin enhances the efficacy of these pharmacologic agents in cervical ripening and labor induction. The efficacy of single- and double-balloon catheters in cervical ripening and labor induction seems similar. To date, the combination of misoprostol with an intracervical catheter seems to be the best approach when balancing delivery times with safety. Although complementary methods are occasionally used by patients, given the lack of data documenting their efficacy and safety, these methods are rarely used in hospital settings.

Hyaluronic acid in Dentoalveolar regeneration: Biological rationale and clinical applications

Background

Hyaluronic acid (HA) is found in different locations in the periodontium, including mineralized tissues (i.e., cementum and alveolar bone) and non-mineralized tissues (i.e., gingiva and periodontal ligament). In addition, it seems to play an essential part in regulating the underlying mechanisms involved in tissue inflammatory reactions and wound healing. HA has the potential to regulate periodontal tissue regeneration and treat periodontal disease.

Aim

The current review of the literature was conducted to assess how HA plays its part in periodontal therapy and examine the contemporary literature's viewpoint on its use in periodontal regeneration.

Conclusion

HA has a multifunctional character in periodontal regeneration, and healing and appears to provide promising outcomes in different periodontal regenerative applications.

Allergic Complications of Hyaluronidase Injection: Risk Factors, Treatment Strategies, and Recommendations for Management

BACKGROUND

Hyaluronidase is used as a reversal agent for hyaluronic acid fillers and to increase the diffusion of other medications after infiltration. Cases of hyaluronidase allergy have been described in the literature since 1984. However, it is still frequently misdiagnosed. This review aims to summarize the current literature to describe the clinical picture of hyaluronidase allergy and identify any risk factors associated with its development, as well as provide recommendations for management in plastic surgery.

METHODS

A digital search of PubMed, Scopus, and Embase databases was performed by two reviewers following the PRISMA guidelines. This search identified 247 articles.

RESULTS

Two hundred forty-seven articles were identified, and 37 of them met the eligibility criteria. One hundred six patients with a mean age of 54.2 years were included in these studies. History of allergy to other substances (timothy grass, egg white, horse serum, penicillin, insect bites, wasp venom, thimerosal, potassium, histamine, phenylmercuric acetate, and nickel) and allergic diseases (asthma, dermatitis, atopy, rhinitis) was reported. A large portion of the patients with a history of repeated exposure (2-4) experienced the symptoms with their second injection. Nonetheless, there was no significant association between time to allergy development and the number of exposures (P = 0.3). Treatment with steroids +/- antihistamines resulted in the rapid and predominantly complete reversal of the symptoms.

CONCLUSIONS

Prior injections or sensitization by insect/wasp venom might be the primary factor associated with hyaluronidase allergy development. The time between the repeated injections is not a likely contributor to the presentation.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Hyaluronidase for Dermal Filler Complications: Review of Applications and Dosage Recommendations

BACKGROUND

Hyaluronidase (Hyal) can reverse complications of hyaluronic acid (HA) fillers, which has contributed substantially to the popularity of such procedures. Still, there are differing opinions regarding Hyal treatment, including dosage recommendations in filler complication management.

OBJECTIVE

We aimed to address unanswered questions regarding Hyal treatment for HA filler complications, including timing and dosage, skin pretesting, properties of various Hyals and interactions with HA gels, and pitfalls of the treatment.

METHODS

PubMed and Google Scholar databases were searched from inception for articles on Hyal therapy for filler complications. Articles were evaluated regarding their contribution to the field. The extensive literature review includes international leaders' suggestions and expert panels' recommendations.

RESULTS

There are limited controlled data but increasing clinical experience with Hyal treatment. The currently used Hyals provide good results and have an acceptable safety profile. Nonemergent complications such as the Tyndall effect, noninflamed nodules, and allergic or hypersensitivity reactions should be treated with low or moderate Hyal doses. Hyal should be considered with prior or simultaneous oral antibiotic treatment in managing inflammatory nodules. Hyal may be tried for granulomas that have not responded to intralesional steroids. Emergent complications such as vascular occlusion and blindness require immediate, high-dose Hyal treatment. Regarding blindness, the injection technique, retrobulbar versus supraorbital, remains controversial. Ultrasound guidance can increase the efficacy of the above interventions.

CONCLUSIONS

Hyal is essential in aesthetic practice because it can safely treat most HA filler complications. Immediate Hyal treatment is required for emergent complications. Aesthetic practitioners should be versed in using Hyal and effective dosage protocols.

Charge-Reversible Nanoparticles: Advanced Delivery Systems for Therapy and Diagnosis

The past two decades have witnessed a rapid progress in the development of surface charge-reversible nanoparticles (NPs) for drug delivery and diagnosis. These NPs are able to elegantly address the polycation dilemma. Converting their surface charge from negative/neutral to positive at the target site, they can substantially improve delivery of drugs and diagnostic agents. By specific stimuli like a shift in pH and redox potential, enzymes, or exogenous stimuli such as light or heat, charge reversal of NP surface can be achieved at the target site. The activated positive surface charge enhances the adhesion of NPs to target cells and facilitates cellular uptake, endosomal escape, and mitochondrial targeting. Because of these properties, the efficacy of incorporated drugs as well as the sensitivity of diagnostic agents can be essentially enhanced. Furthermore, charge-reversible NPs are shown to overcome the biofilm formed by pathogenic bacteria and to shuttle antibiotics directly to the cell membrane of these microorganisms. In this review, the up-to-date design of charge-reversible NPs and their emerging applications in drug delivery and diagnosis are highlighted.

Changes of the salivary and serum proteome in canine hypothyroidism

In this study, changes in salivary and serum proteome of dogs with hypothyroidism were studied using tandem mass tags (TMT) labelling and liquid chromatography-mass spectrometry (LC-MS/MS). Saliva and serum proteome from 10 dogs with hypothyroidism were compared with 10 healthy dogs. In saliva, a total of seven proteins showed significant changes between the two groups, being six downregulated and one upregulated, meanwhile, in serum, a total of six proteins showed significant changes, being five downregulated and one upregulated. The altered proteins reflected metabolic and immunologic changes, as well as, skin and coagulation alterations, and these proteins were not affected by gender. One of the proteins that were downregulated in saliva, lactate dehydrognease (LDH), was measured by a spectrophotometric assay in saliva samples from 42 dogs with hypothyroidism, 42 dogs with non-thyroid diseases and 46 healthy dogs. The activity of LDH was lower in the saliva of hypothyroid dogs when compared to non-thyroid diseased dogs and healthy controls. This study indicates that canine hypothyroidism can produce changes in the proteome of saliva and serum. These two sample types showed different variations in their proteins reflecting physiopathological changes that occur in this disease, mainly related to the immune system, metabolism, skin and coagulation. In addition, some of the proteins identified in this study, specially LDH in saliva, should be further explored as potential biomarkers of canine hypothyroidism.

Capillary leak and endothelial permeability in critically ill patients: a current overview

Capillary leak syndrome (CLS) represents a phenotype of increased fluid extravasation, resulting in intravascular hypovolemia, extravascular edema formation and ultimately hypoperfusion. While endothelial permeability is an evolutionary preserved physiological process needed to sustain life, excessive fluid leak-often caused by systemic inflammation-can have detrimental effects on patients' outcomes. This article delves into the current understanding of CLS pathophysiology, diagnosis and potential treatments. Systemic inflammation leading to a compromise of endothelial cell interactions through various signaling cues (e.g., the angiopoietin-Tie2 pathway), and shedding of the glycocalyx collectively contribute to the manifestation of CLS. Capillary permeability subsequently leads to the seepage of protein-rich fluid into the interstitial space. Recent insights into the importance of the sub-glycocalyx space and preserving lymphatic flow are highlighted for an in-depth understanding. While no established diagnostic criteria exist and CLS is frequently diagnosed by clinical characteristics only, we highlight more objective serological and (non)-invasive measurements that hint towards a CLS phenotype. While currently available treatment options are limited, we further review understanding of fluid resuscitation and experimental approaches to target endothelial permeability. Despite the improved understanding of CLS pathophysiology, efforts are needed to develop uniform diagnostic criteria, associate clinical consequences to these criteria, and delineate treatment options.

Identification, quantification, and structural role of N-glycans in two highly purified isoforms of sheep testicular hyaluronidase

Animal-derived hyaluronidase, which hydrolyzes the polysaccharide hyaluronic acid, has been used in medical applications despite its limited purity. Additionally, the N-glycan characterization of sheep testicular hyaluronidase (STH) and its structural role remain poorly understood. In this study, STH was purified from the commercially available STH preparation (containing at least 14 impurity proteins) using heparin-affinity chromatography followed by size exclusion chromatography. The structure and quantity of N-glycans of STH were investigated using liquid chromatography-electrospray ionization-high energy collision dissociation-tandem mass spectrometry. Two isoforms, H3S1 and H3S2, of STH were obtained (purity >98 %) with a yield of 3.4 % and 5.1 %, respectively. Fourteen N-glycans, including nine core-fucosylated N-glycans (important for the stability and function of glycoproteins), were identified in both H3S1 and H3S2, with similar quantities of each N-glycan. The amino acid sequences of the proteolytic peptides of H3S1 and H3S2 were compared with those reported in STH. The hyaluronic acid-degrading activity of deglycosylated H3S1 and H3S2 was reduced to 70.8 % and 71.1 % compared to that (100 %) of H3S1 and H3S2, respectively. This is the first report of N-glycan characterization of two highly purified isoforms of STH. These H3S1 and H3S2 will be useful for medical use without unwanted effects of partially purified STH.